Sen. Mitt Romney, R-Utah, said Friday that he was “sickened” by what he read in special counsel Robert Mueller’s report on Russian interference in the 2016 election and Donald Trump’s attempts to cover it up.

In a scathing statement posted to Twitter, Romney became one of the first Republican members of Congress, and the most prominent, to criticize the Trump administration and the president for the behavior detailed by Mueller.

“It is good news that there was insufficient evidence to charge the President of the United States with having conspired with a foreign adversary or with having obstructed justice. The alternative would have taken us through a wrenching process with the potential for constitutional crisis. The business of government can move on,” Romney wrote. “Even so, I am sickened at the extent and pervasiveness of dishonesty and misdirection by individuals in the highest office of the land, including the President. I am also appalled that, among other things, fellow citizens working in a campaign for president welcomed help from Russia — including information that had been illegally obtained; that none of them acted to inform American law enforcement; and that the campaign chairman was actively promoting Russian interests in Ukraine.”

Former Trump campaign chairman Paul Manafort was sentenced to 7 and a half years in prison following his conviction on financial fraud charges. The Mueller report detailed Manafort’s work in the Ukraine on behalf of Russian interests.

Mueller’s report also laid out numerous contacts between members of Trump’s 2016 campaign and family members with Russians, some of whom offered information deemed helpful in electing the billionaire. It also painted a picture of Trump as a man desperate to keep those ties hidden from the public.

“If we had confidence after a thorough investigation of the facts that the president clearly did not commit obstruction of justice, we would so state,” Mueller wrote. “Based on the facts and the applicable legal standards, however, we are unable to reach that judgment.”

Romney, the Republican nominee for president in 2012, said reading the report proved difficult.

“Reading the report is a sobering revelation of how far we have strayed from the aspirations and principles of the founders,” Romney wrote.

Romney had been sharply critical of Trump’s business practices, temperament and foreign policy proposals during the 2016 primaries. But when Trump endorsed him for his Senate bid last year, Romney happily accepted.